Motive-fluid-operated hammer.



Patented 1an. -29,` 490|.

c. H. JOHNSON. MDTIVE FLUID O PERATED HAMMER.

(Application filled Mt. 2, 1900.)

(N0 Nudel.)

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CHARLES HARRIS JOHNSON, OF CHICAGO HEIGHTS, ILLINOIS, ASSIGNOR TO THEJOHNSON, PARFITT TOOL COMPANY, OF SPRINGFIELD, ILLINOIS.

lVlOTlVE-FLUID-OPERATED HAMMER.

SPECIFICATION-forming part of Letters Patent No. 666,757, dated January29, 1901. Application filed March 2, 1900. Serial No. 7,081. (No model.)

To all wiz/m, it may concern: of the lever L or in other suitablemanner,

Be it known that I, CHARLES HARRIS JOHN- and said motive-duid passage aof the han- SON, a citizen of the United States, residing dle connectswith the motive-fluid passage b, at Chicago Heights, in the county ofCook, having the port b delivering into the cylin- 55 State of Illinois,have invented certain new der B.

and useful Improvements in Motive-Fluid- The handle A and throttle-valveT may be Operated Hammers; and Ihereby declare vthe of an approvedconstruction, excepting that following to be a full, clear, and exactdescripin order to secure the handle to the cylinder tion of the same,reference being had to the in a simple and effective manner I form the6o a accompanying drawings, in Whichhandle with a flange l, whichreceives the Figure l is a longitudinal central section end of thecylinder B, and with an internal of a pneumatic hammer embodying myincollar 2, which takes over the end of the cylvention; and Fig. 2 is asectional view of part inder B and is pinched between the end of of thecylinder and the piston or hammer, the cylinder and the flange of thecap D, 65 showingamodication in the arrangement of which closes thecylinder When said cap is the supplemental supply or admission port ofin position. In order to lock the cap D and the piston. handle A to thecylinder B, I form a catch-l Like symbols refer to like parts whereverpocket 3 in the handle of the cylinder for the they occur. reception ofa spring-pressed ratchet-dog 4, 7o

zo My invention relates generally to the con- Which engages a suitablenotch in the head struction of what are termed valveless moof cap D, andsaid dog is confined in said tive-fluid-operated tools, and especiallyto pocket by an annular screw-plug 5, the free pneumatic hammers, andhas for one of its end of the dog being bent at right angles, as objectsa gradual admission of the motive at 4, and the screw-plug 5 and handleA hav- 75 z5 iiuid behind the piston or hammerduring poring acorresponding recess or seat for the retions of its return and forwardstrokes, whereception of the bent end of dog 4 when the dog by greaterpower is obtained and recoil obis in position to lock the partstogether. viated. In carrying out this part of my in- B indicates thehammer-cylinder, provided vention I provide the piston with a supplewitha supply-port b and an exhaust-port b2, 8o

3o mental inlet or admission port so arranged, and in case a shoulderedpiston is used the as to admit motive duid .to the end of the bore ofthe cylinder is contracted between the piston before one-half of thereturn stroke of ports b and b2, as at 6, to receive that portion thepiston is completed, and such a construcof the piston having the leastdiameter. tion embraces one feature of my invention. v@indicates apiston of diameters suitable to 85 In order to obtain the best results,I have iit the internal diameters of the cylinder B, found that thesupplemental admission-port said piston having the channel or passage 7should bear a relative proportion to the exand the ports 8 extendingthrough its walls, haust-ports of about one to six or one to four, whichport-s 8 are exhaust-ports and may also and such a construction embodiesa further be supply-ports, according to the position of 9o 4o feature ofmy invention. There are other the piston (or hammer) within the cylinderminor features of invention, all as will hereand accordingly as theyregister with the supinafter more fully appear. ply-port b' orexhaust-port b2 of said cylinder.

I will now proceed to describe my invention In addition to said ports 88 I provide the by reference to the drawings, so that others piston withone or more supplemental supply 95 skilled in the art to which itappertains may or admission ports 9, so arranged therein as apply thesame. to open or register with the supply-port of the In the drawings, Aindicates the handle, B cylinder before one-half of the return strokethe cylinder, and C the piston, of a pneumatic of the piston has beeneffected, and such suphammer. The handle A has the motive-fluidplementalport or ports may be made directly roo 5o supply passage c, controlledby a suitable through the walls of the piston, as shown atthrottle-valve T,-which is operated by means 9 in Fig. l of thedrawings, or may be in the form of a groove orlohannel on the peripheryof the piston, as indicated at 9 in Fig. 2 of the drawings, and ineither case said supplemental port will not register with the supplyportof the cylinder until the main ports 8 are closedfas to the exhaust-portb2 of the cylin-` der, and therefore said supplemental ports 9 (or 9a)will never act as exhaust-ports.

The supplemental admission-port 9 (or 9a) should be of such size that itwill not admit the motive fluid so rapidly as to arrest the motion ofthe piston before it has moved as far after said vport is opened as ithad previously moved under the impulse due to the pressure of the motiveduid at the other end of the piston-as, for instance, in the case of ashouldered piston such as shown in the drawings the port 9 (or 9a)should not be so large as to admit -sufcient pressure to counterbalancethe pressure on the shoulderof the piston and arrest its movement beforethe piston-port 8 has registered with theinlet-port b' of the cylinderon the return stroke ofthe exceed the proportions of one (l) to four(4.)

The construction being substantiallysuch as hereinbefore pointed out,the operation of the machine will be as follows: The piston C being inthe position shown in the drawings 1 and the throttle T having beenopened 'to admit the motive iiuid to the cylinder, the m0- tive fiuidentering through port b will act upon the shoulder of the piston (orupon the corresponding piston-head) to cause the return stroke of thepiston, andwhen the return movement of the piston has closed the ports 8of the piston with relation to exhaust-port b2 of the cylinder thesupplemental admission-port 9 (or 9, Fig. 2) will have opened to thesupply-port b of the cylinder, vwhereupon fluid-pressure (dependent onthe size of port 9 or 91) will be gradually admitted to the opposite endof the piston, the piston still continuing its returm movement, untilsufficient pressure has been admitted through port-'9 to arrest thebackward movement of the piston, which will then be reversed and makeits lforward stroke. The small supplemental admission-port 9 (or 9a)will upon the reverse (or working) stroke of the piston supply themotive-duid pressure, which will thereafter follow up the piston andsomewhat augment the force of the blow. The supplemental supply oradmission port 9 (or 9a) will "be closed before the piston-ports 8 8open to the exhaust-port b2 of the cylinder, so that the supplementaladmission-port (9 or 9) never acts as an exhaust-port, though the mainports S 8 of the piston may, if desired, be arranged to servealternately as supply and exhaust ports. Y

Among the advantages incident to my invention are simplicity ofconstruction, effl-` ciency in operation, somewhat increased power, andthe avoidance of objectionable recoil.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is-

l. The combination with a cylinder having supply and exhaust ports, of apiston having a supplemental supply-port so arranged with relation tothe exhaust port or ports as to maintain a gradual ad mission ofpressure over a large part of the return and forward strokes of .thepiston, substantially as and for the purposes specified.

2. In a motive-fluid-operated tool, the combination with a cylinderhaving supply and exhaust ports,of -a-shouldered piston having admissionand exhaust ports which control the admission-and-exhaust of thelinotiveduid to the head of the piston above 'the shoulder one ofsaid'portsfbeing an admission-port only, substantially as and for thepurposes specified.

3. In a ymotive-fluid-operated tool, the combination `v with acylinderhaving supply and exhaust ports, of a shouldered piston having aplurality of 'ports someof which are supply- Vports only and which controlthe admission ofthe motive fluid to Athe head of the piston above theshoulder while others are alternatel'y supply and lexhaust ports,substantially as and for 'the `purposes specified.

4. In a motive-Huid tool, the combination with a cylinder of a pistonhaving a supplemental supply-port, admission and 4exhaustports-controlling the admission and release of the motive fluid to andfrom the cylinder, the supplemental supply-port being of less thanone-quarterthe cross area ofthe exhaustports, substantially as and forthe "purposes specified.

5. In a motive-fluid tool, the combination -witha cylinder having supplyand exhaust ports,of apiston having aplurality of ports, oneof which isa supply-port only, and which does vnot exceed one-fourth the cross areaof the exhaust-ports, substantially as and for the purposes specified.

6. In a motive-uid-operated tool, the combination with acylinder, a capfor closing the end thereof, of a spring-dog adapted lto engage fthescrew-cap and provided with a free end which projects at an angle-to thedog, an annular screw-'plug for conining the springdog-said screw-plughaving a slot or recess for receiving the bent free end of the dog,substantially as and for the purposes specified.

7. In a motive-fluid-operated tool, the combination with a cylinder,afcap for closing the end thereof, a handle having a ring or collarclamped between the flange of the screw-cap and the end of the cylinder,of a spring-dog adapted to engage the screw-cap and provided with a-free end which 'projects at an angle to the dog, an annular screw-plugfor confining the spring-dog-said screw-plug and handle IOO IIO

having a slot or recess for receiving the bent free end of the dog,substantially as and for the purposes specified.

S. The 'combination With a cylinder having 5 supply and exhaust ports,of a piston having a supply-port arranged to gradually admit pressureover a large part of the return and forward strokes of the piston, andan exhaustport arranged to be opened by the movement l of the piston,substantially as and for the purio poses specified.

In testimony whereof I ax my signatur@ in presence of two witnesses,this 21st day of February, 1900.

CHARLES HARRIS J OHNSON; Witnesses:

H. H. VAUGHAN, GEORGE I. MCELDOWNEY.

